Registry maintenance for stackedboard transfer



Dec. 6, 1966 H. D. KELLEY 3,289,311

REGISTRY MAINTENANCE FOR STACKEDBQARD TRANSFER Filed Feb. 12, 1965 Sheets-$heet l BUNDLER IN! 111w T1) A" HUGH D. KELLEY M/Qw $3M Dec. 6, 1966 H. D. KELLEY 3,239,311

REGISTRY MAINTENANCE FOR STACKED'BOARD TRANSFER Filed Feb. l2, 1965 2 Sheets-Sheet 2 m mv m R. HUGH D. KELLEY MQMAQM AHorn 2 9 United States Patent 3,289,811 REGISTRY MAINTENANCE FOR STACKED- BOARD TRANSFER Hugh D. Kelley, Enterprise, Kans., assignor to The J. B. Ehrsam & Sons Manufacturing Company, Enterprise, Kane, a corporation of Kansas Filed Feb. 12, 1965, Ser. No. 432,314 10 Claims. (Cl. 19835) The present invention relates to means for maintaining registry of stacked articles during acceleration of conveyor means upon which such articles are carried. The mechanism has been designed for use in connection with a system of handling plaster board sheets, or the like, involving a hooker and conveyor means for transferring booked boards to a bundle, and the invention has been illustrated and will be described in that environment; though it will be recognized that the invention is applicable, as well, in other environments in which similar problems are encountered.

The primary object of the invention is to provide simple, inexpensive means to prevent inertial. dislodgment or shifting of a superposed article, relative to a similar article directly resting on a conveyor, resulting from rapid acceleration of the conveyor. A further object of the invention is to provide such means which may be readily added as an accessory to existing transfer mechanisms.

A more specific object of the invention is to rovide registry maintenance means of the character described which shall be so constructed and designed as to be effective to maintain registry of booked plaster boards without damaging the boards.

Still further objects of the invention will appear as the description proceeds.

To the accomplishment of the above and related objects, my invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustartive only, and that change may be made in the specifice construction illustrated and described, so long as the scope of the appended claims is not violated.

FIG. 1 is a somewhat diagrammatic plan view of board handling mechanism including a supply conveyor, and a multiple belt transfer conveyor for delivering boards, in sideby-side relation, from the supply conveyor to a hooker and for transferring the boards, after booking, to a bundler, showing my registry maintenance means associated therewith;

FIG. 2 is a somewhat enlarged fragmentary end elevation of a conventional. hooker and an associated portion of a transfer conveyor, illustrating the problem to the solution of which the present invention is directed;

FIG. 3 is an enlarged, fragmentary section taken substantially on the line 3-3 of FIG. 1;

FIG. 4 is a fragmentary section taken substantially on the line 44 of FIG. 3; and

FIG. 5 is a fragmentary perspective view of parts of the registry maintenance means of the present invention.

Referring more particularly to FIG. 1, the reference numeral indicates generally a conventional, live-roll conveyor upon which pairs of boards 11 and 12 are brought into the illustrated mechanism in side-by-side relation. According to conventional practice, when a pair of boards reaches proper registry with a multiple-belt conveyor indicated generally by the reference numeral 13, the roll conveyor bed is lowered to deposit the boards on the upper runs of the several belts 14, 15, 16, 17 and 18 of the conveyor 13. Thereupon, the motor 19 is enerigzed to drive the several belts at high speed toward the right as viewed in FIG. 1 to transfer the boards to a conventional booker indicated generally by the reference numeral 20. When the space between the boards 11 and 12 coincides with the center line of the booker 20, the conveyor 13 is automatically stopped, leaving the board 11 substantially in registry with the arms 22 and the board 12 substantially in registry with the arms 21 of the hooker.

The arms 21 and 22 are mounted upon rock shafts 23 and 24 which are actuable by fluid motors 25 and 26 to swing the arms in opposite directions upwardly and to- Ward each other about the axes of the shafts 23 and 24. Thus, the boards are lifted off the belts of the conveyor 13 and tilted toward each other. The hooker is so designed that the arm 21 swings farther than docs the arm 22, so that the board 12 is transferred, in facing relation, onto the top of the board 11, whereafter the arms 21 and 22 are returned to their illustrated position with the board 12 resting, in accurate registry, upon the board 11; and as the arms 22 reach their illustrated position, the booked board pair is redeposited upon the conveyor 13. Now the motor 19 is again energized; and in conventional practice the belts of the conveyor 13 are very rapidly accelerated in order to transfer the booked boards as rapidly as possible to the bundler 27. Since the finished faces of the boards 11 and 12 which are in contact with each other are intentionally quite smooth, while the belts are of a character known as rough top and are made of a medium hardness rubber having excellent gripping characteristics, the board 11 is entrained with the belts substantially without slippage during such acceleration, but the inertia of the board 12 almost invariably causes that board to lag behind the board 11 whereby the board 11 moves out of accurate registry with the board 12 frequently by as much as six or seven inches. As a consequence, the boards are delivered to the bundler 27 in improper relation, and difficulty arises in the performance of the bundling step.

According to the present invention, means is provided to exert a forward force upon the trailing edges of both boards 11 and 12 throughout the period of acceleration of the conveyor 13, effectively to overcome that inertial effect and to maintain accurate registry of the two boards. Of course, after the conveyor 13 reaches its maximum velocity, the inertial effect disappears, and the force-exerting means may be withdrawn.

A preferred embodiment of such force-exerting means is indicated generally by the reference numeral 28, and it will be seen, upon inspection of FIG. 1, that one or more of such mechanisms may be associated with the board handling assembly. Conventionally, the conveyor 13 comprises a support table 29 for the upper run of each of its belts, and according to the present invention, a bracket 30 having an elongated table portion 31 disposed slightly below the common plane of. the upper runs of the several belts may be suitably secured to any one or more of said supports 29. As shown, the table section 31 of each bracket is provided with an upstanding guide rail 32 for a purpose which will appear.

An adjustable plate 33 is secured to the bracket 30 and assists in the journal mounting of a shaft 34 which, as is clearly to be seen in FIG. 1, is arranged on a horizontal axis, transverse with respect to the direction of movement of the conveyor 13, below the table 31 and slightly to the left of the center line of the hooker 20. A sprocket 35 is carried by the shaft 34 in alignment with the guide rail 32. A second shaft 36 is mounted with its axis in the same horizontal plane, and parallel with, the axis of the shaft 34 and spaced to the right from the shaft 34 approximately to the point at which the trailing edges of boards on the conveyor 13 have attained maximum velocity as they travel on the conveyor 13 toward the 3 bundler 27. A second sprocket 37 is drivingly carried by the shaft 36.

An endless chain 38 is trained about the sprockets and 37 with its upper run 39 closely adjacent the common plane of the upper runs of the belts of the conveyor 13 and with its lower run 40 more remote therefrom. The chain 38 is preferably of the Well-known roller-link type and may be guided, as its upper run traverses the table 31, by straddling the rail 32. A pusher 41 is fixed to one of the links of the chain 38 as at 42. As is clearly to be seen in FIGS. 3 and 5, said pusher extends transversely and oppositely from the chain 38 and is provided with a median seat portion 43 which bears on the chain to inhibit tilting of the pusher forwardly, a bifurcated foot portion 44 which bears on the table 31 when the pusher is located on the upper run of the chain to prevent rearward tilting, and an upwardlyextending, substantially vertical face 45 whose vertical dimension exceeds the combined height of booked boards or other stacked articles on the conveyor 13.

At its end remote from the sprocket 35, the shaft 36 carries another sprocket 46 driven by a chain 47 trained about the sprocket 46 and about a sprocket 48 on a jack shaft 49. As is to be seen in FIG. 1, a motor 50, independent of the motor 19, is connected by a chain 51 to drive a sprocket 52 which is loose on the jack shaft 49; and a fluid clutch 53, controlled through a solenoid valve 54 in a supply line 55 from a compressor 56, is operable to establish and to disestablish a driving connection between the sprocket 52 and the shaft 49. The clutch 53 is of the well-known controlledslipping type. That is, when deactivated, the clutch will wholly release the sprocket 52 from driving connection with the shaft 49; but when activated the clutch will provide a limited-torque driving connection betwen the sprocket 52 and the shaft 49. Preferably such clutch will include an adjustment operable to vary the torque transmission capacity of the mechanism.

A second solenoid valve 57 in the supply line 55 controls a brake 58 associated with the shaft 49.

A switch 59 is so mounted that its actuating arm 60 is engageable by the board 11 when said board is deposited on the conveyor 13 by the booker arm 22; and a second switch 61 is so disposed that its actuating arm 62 will be engaged by the pusher 41 substantially at the return end of the lower run 40 of the chain 38. The switches 59 and 60 jointly control the solenoid valves 54 and 57. The switch 59 is oi? such character that it will be effective only upon alternate actuations of its arm 60.

With the registry-maintenance means of the present disclosure operatively installed in the assembly of FIG. 1, and with the chain 38 in the dotted line position of the pusher 41 in FIG. 3, the clutch 53 is in deactivated condition so that the chain 38 is stationary. When the boards 11 and 12 have advanced from their solid line positions in FIG. 1 to a point at which their lower ends are substantially in registry with the belt 18 of the conveyor 13, the roll conveyor bed will be lowered whereby said boards will be deposited upon the conveyor 13. Now, the motor 19 is energized and the boards are transferred to their broken line positions shown in FIG. 1. As the boards reach those positions, the board 11 will engage and depress the switch arm 60 but without affecting the switch. Now the conveyor 13 will stop and the booker 20 will be actuated to move the boards into faceto-face relation and to deposit the booked boards again on the conveyor 13. As the boards are lifted by the booker, the switch arm 60 is released; and as they are redeposited on the conveyor the switch arm will again be depressed by the board 11. This time, depression of the switch arm 60 actuates the valves 54 and 57 to release the brake 58 and engage the clutch 53. Instantly, the chain 38 will be driven to move the pusher from its broken line position in FIG. 3 and into engagement with the trailing edges of the boards 11 and 12. The setting of the clutch 53 is such that, if the trailing edge of the board 12 is at this time behind the trailing edge of the board 11, the pusher 41 will exert suflicient force against the board 12 to move its edge into registry with that of the board 11; but the power exerted through the pusher 41 is insufiicient to move the board 11 relative to the conveyor 13. Immediately after engagement of the pusher 41 with the trailing edges of the boards, the motor 19 will be reenergized rapidly to accelerate the conveyor 13. The drive train from the motor 50 to the chain 38 is of such character that, if the pusher 41 encountered no resistance, it would be driven in the direction of movement of the conveyor 13 at a velocity exceeding the maximum velocity of the conveyor 13. Because the pusher is in contact with the trailing edges of the boards 11 and 12, and because of the presence of the slipping clutch 53 in the pusher drive train, however, the pusher cannot, while in engagement with the boards, move at a velocity exceeding that of the boards on the conveyor 13; but the pusher will be held in force-exerting contact with the trailing edges of the boards throughout the acceleration of the conveyor 13, whereby inertial slippage of the board 12 is prevented.

As the conveyor, and the booked boards thereon, attain maximum velocity, the trailing edges of the boards pass beyond the shaft 36 and the pusher 41 travels around the sprocket 37 whereby it is withdrawn from its engagement with the board edges.

When the pusher reaches the return end of the lower run 40 of the chain 38, it engages and moves the arm 62 of the switch 61 to deactivate the clutch 53 and apply the brake 58, thus completing one full cycle of the registry-maintenance mechanism.

I claim as my invention:

1. The combination with conveyor means, means for depositing on said conveyor means a plurality of similar articles in stacked relation, and means for rapidly accelerating said conveyor means, of follower means engageable with the trailing edges of all of the articles in a single stack and driving means independent of said accelerating means and operatively connected to drive said follower means in the line of acceleration of said conveyor means, during such acceleration, at a velocity equal to that of said conveyor means to maintain registry of said trailing article edges.

2. The combination with conveyor means, means for depositing on said conveyor means a plurality of similar articles in stacked relation, and means for rapidly accelerating said conveyor means, of follower means mounted above said conveyor means to travel in the line of such acceleration, said follower means being engageable with the trailing edges of all of the articles in a stack on said conveyor means, power means independent of said accelrating means, and a drive train including a controlledslipping connection, operatively connecting said power means to drive said follower means in the direction of such acceleration at a velocity exceeding the maximium velocity of said conveyor means, except when said follower means is engaged with the bottom article of such a stack.

3. In combination, a conveyor comprising a longitudinally-driven web, means for intermittently driving said web, an endless strand having one run adjacent and parallel with said web and its opposite run more remote from said web, means including a controlled-slipping connection for driving said one run of said strand in the direction of travel of said web at a velocity exceeding the maximum velocity of said web, and pusher means carried by said strand and located, when on said one run, closely above said web, said controlled-slipping connection being so constructed and arranged that, when said pusher means engages an article supported in direct contact with said conveyor means, said driving means will drive said one run at a velocity equal to that of said conveyor.

4. In combination, a conveyor comprising a plurality of laterally-spaced, longitudinally--driven webs disposed substantially in a common plane, means for intermittently driving all of said webs at a common velocity, an endless strand disposed between two adjacent ones of said Webs with an upper run close to said plane and a lower run more remote from said plane, means including a controlled-slipping connection for driving said upper run of said strand in the direction of travel of said webs at a velocity exceeding the maximum velocity of said webs, and pusher means carried by said strand and located, when on said upper run of said strand, closely above said common plane, said controlled-slipping connection being so constructed and arranged that, when said pusher means engages an article supported in direct contact with said conveyor means, said driving means will drive said upper run at a velocity equal to that of said conveyor.

5. In combination, a conveyor comprising a plurality of laterally-spaced endless belts having their upper runs disposed in a common plane, means for intermittently driving said belts to move their upper runs in a common direction at a common velocity, two parallel shafts disposed in a plane below and parallel with said common plane, and spaced apart in the direction of travel of said belt runs, two rotors respectively mounted on said shafts, between adjacent ones of said belts, for rotation about the respective axes of said shafts, a continuous strand trained over said rotors, the upper run of said strand being closely adjacent said common plane and the lower run thereof being more remote from said plane, means for driving one of said rotors in a direction and at a velocity to move the upper run of said strand in the direction of travel of the upper runs of said belts at a velocity exceeding the maximum velocity of said belts, the drive train between said last-named means and said strand including a controlled-slipping connection, and pusher means carried by said strand and located, when on the upper run thereof, above said common plane, said controlled-slipping connection being so constructed and arranged that, when said pusher means engages an article supported in direct contact with said conveyor means, said driving means will drive said upper run at a velocity equal to that of said conveyor.

6. In a board handling system, a hooker operative, upon delivery thereto of two boards in side-by side relation, to lay the trailing one of said boards on top of the leading one of said boards, a plural-belt conveyor passing said booker so to deliver boards thereto and to remove booked boards therefrom, means for intermittently driving said conveyor, and means automatically operative to exert forward pressure against the trailing edges of booked boards on said conveyor during acceleration thereof.

7. In a board handling system, a booker operative, upon delivery thereto of two boards in side-by-side relation, to lay the trailing one of said boards on top of the leading one of said boards, a plural-belt conveyor passing said booker so to deliver boards thereto and to remove booked boards therefrom, means for intermittently driving said conveyor, a pair of parallel shafts arranged below the upper run of said conveyor upon axes transverse to the line of movement of said conveyor, one of said shafts being disposed rearwardly of the point at which the booker deposits the trailing edges of booked boards on said conveyor and the other of said shafts being disposed forwardly beyond the point at which the trailing edges of booked boards have attained maximum velocity with the discharging travel of said conveyor, two sprockets respectively mounted on said shafts between an adjacent pair of said belts, an endless chain trained over said sprockets and having an upper run close to the plane of said conveyor upper run and a lower run more remote from said conveyor upper run, pusher means carried by said chain and located, when on the upper run of said chain, above the plane of said conveyor upper run, and power means connected to drive said sprockets, through a controlled-slipping connection, in a direction and at a velocity to move said upper run of said chain in the direction of travel of said upper conveyor run at a velocity exceeding the maximum velocity of said upper conveyor run.

8. The board handling system of claim 7 including means actuated by the deposit of booked boards on said conveyor to initiate driving of said sprockets, and means actuated by travel of said chain through one complete cycle to stop said chain.

9. The board handling system of claim 7 in which said controlled-slipping connection comprises a slipping clutch, means actuated by deposit of booked boards on said conveyor to activate said clutch, and means actuated by travel of said chain through one complete cycle to deactivate said clutch.

10. The board handling system of claim 7 in which said controlled-slipping connection comprises a slipping clutch, means actuated by deposit of booked boards on said conveyor to activate said clutch, and means engaged by said pusher means when said pusher means is close to the return end of the lower run of said chain to deactivate said clutch.

References Cited by the Examiner UNITED STATES PATENTS 1,934,087 11/1933 Payzout et al.

2,667,259 1/1954 Parker l98-35 X 3,053,373 9/1962 Cross et a1. l98l68 X 3,174,612 3/1965 Jones l98168 X EVON C. BLUNK, Primary Examiner.

R. E. KRISHER, A. C. HODGSON, Assistant Examiners. 

1. THE COMBINATION WITH CONVEYOR MEANS, MEANS FOR DEPOSITING ON SAID CONVEYOR MEANS IN PLURALITY OF SIMILAR ARTICLES IN STACKED RELATION, AND MEANS FOR RAPIDLY ACCELERATING SAID CONVEYOR MEANS, OF FOLLOWER MEANS ENGAGEABLE WITH THE TRAILING EDGES OF ALL OF THE ARTICLES IN A SINGLE STACK AND DRIVING MEANS INDEPENDENT OF SAID ACCELERATING MEANS AND OPERATIVELY CONNECTED TO DRIVE SAID FOLLOWER MEANS IN THE LINE OF ACCELERATION OF SAID CONVEYOR MEANS, DURING SUCH ACCELERATION, AT A VELOCITY EQUAL TO THAT OF SAID CONVEYOR MEANS TO MAINTAIN REGISTRY OF SAID TRAILING ARTICLE EDGES. 